1. Field of the Invention
The present invention is directed to the field of battery powered heating devices such as battery powered soldering irons. An exemplary version of such a device is disclosed in U.S. patent application Ser. No. 10/892,780, filed on Jul. 15, 2004, titled: “Soldering Device with Cartridge Type Battery Pack”, hereby incorporated by reference. The present invention is more particularly directed to a control system to monitor and control the delivery of power to the heating device so as to provide the power necessary for utilization of the device yet reduce or minimize the battery drain and any unnecessary expenditure of power, and thereby maximize the battery life.
2. General Background and State of the Art
Soldering irons are used to make secure electrical connections by melting solder and allowing the solder to bond between two electrical devices such as wires and contact points of a circuit. A number of different types of soldering irons are in wide-spread use and have been available for a number of years. Desoldering devices are used to melt soldered connections and allow an electrical device to be removed and replaced.
Most soldering and desoldering devices are powered by electrical current, and particularly for industrial applications, the soldering devices use an AC power source. However, there are a few battery powered soldering devices that are available though their performance is somewhat limited. Examples are shown in U.S. Pat. Nos. 2,973,422; 3,141,087; 3,141,956; 4,064,447 and 5,446,262. In addition, to provide flexibility in a soldering device that has no electrical power connection requirement, there are soldering devices that utilize a gaseous fuel to heat a soldering tip through for example a catalyst or an open flame, as shown for example in U.S. Pat. Nos. 5,799,648 and 5,921,231.
While the devices according to the prior art may be able to provide cordless soldering capabilities, they do not provide control systems to minimize the amount of power utilization to extend the battery life. Accordingly, it would be desirable to provide a control system on a battery powered heating device which would minimize the unnecessary expenditure of battery power during periods when the device is turned on yet not being utilized.
The present invention is directed to a control system and method of controlling a battery powered heating device such as a soldering or desoldering tool that includes a control circuit to control the delivery of power to a cartridge heating tip and to cycle the power to the cartridge heating tip during times of no use so as to minimize the amount of power expended to maintain the device in a ready or usable state. The present invention provides an easy control system for a mobile temperature-controlled battery-powered heating device the performance of which is not influenced by battery voltage dissipation as the control system supplies suitable cycles of power depending on both the battery voltage and the steps of heating job loads.